A bagel can be a treat from a coffee shop, a dependable refreshment during morning meetings at work or a snack at other times during the day. Bagels can be healthy choices if you eat them in moderation as part of a nutritious diet, but they can be poor choices if you eat too many of them or eat them with high-fat or high-sugar toppings. Bagels are high-carbohydrate choices, so eat them with lower-carbohydrate accompaniments to balance your meal or snack.The size and type of your bagel affect its calorie content. A small, 1-ounce, plain bagel has 73 calories, while a large, 4.5-ounce plain bagel has 337 calories. Sweetened bagels, such as cinnamon-raisin and blueberry, can have additional calories from added sugars, and bagels with cheese are also higher in calories. In comparison, a 1-ounce slice of whole-wheat bread has 71 calories, and a whole-grain English muffin has 134 calories. To keep your calorie consumption under control, choose a small bagel, or eat only half of a larger one.A 1-ounce bagel has 14 grams of carbohydrates, and a large, 4.5-ounce bagel has 53 grams. Carbohydrates are the main source of energy in the diet, providing 4 calories per gram. They should provide 45 percent to 65 percent of calories in a balanced diet to improve your chances of maintaining your weight in the long term. Bagels are nearly fat-free, and a 1-ounce bagel provides 3 grams of protein, or 6 percent of the daily value for protein. White bagels provide 0.6 gram of fiber per ounce, and whole-wheat bagels provide 4 grams of fiber per ounce. A high-fiber diet can reduce your risk for heart disease. Adding cooked egg whites and avocado slices to your bagel increases the content of protein and healthy fats.A 1-ounce bagel provides 1.7 milligrams of iron, or 9 percent of the daily value, and a 1-ounce whole-wheat bagel provides 2.7 milligrams of iron, or 15 percent of the daily value. Iron is a necessary mineral for your body to produce healthy red blood cells and prevent anemia. Whole grains are natural sources of iron, and enriched and fortified whole and refined grains have iron added to them. Enriched and fortified white and whole-wheat bagels also contain vitamin B-1, vitamin B-2, vitamin B-3 and folic acid. Eat your bagel with peanut butter and fruit to increase the vitamin content.The overall nutrition information of your meal or snack with a bagel depends on what you eat with your bagel. Spreading 2 tablespoons of full-fat cream cheese on your bagel adds 100 calories and 6 grams of saturated fat, which raises levels of unhealthy low-density lipoprotein, or "bad" cholesterol, in your blood and increases your risk for heart disease. But a 2-tablespoon serving of fat-free cream cheese plus an ounce of sliced turkey meat together add 66 calories, less than 1 gram of fat and 10 grams of protein.